The subject invention relates to an air conditioning system for a vehicle, frequently referred to as a heating, ventilating and air conditioning (HVAC) system.
Such systems typically include a compressor for compressing a refrigerant, a condenser for condensing the refrigerant, an evaporator for evaporating the refrigerant, a discharge fluid line interconnecting the compressor and the condenser, a liquid fluid line interconnecting the evaporator and the condenser, and a suction fluid line interconnecting the evaporator and the compressor. Such systems utilize various valve arrangements for controlling flow through the system during operation and during shutdown and/or in response to a leak of refrigerant in the system. Some systems employ valves for bypassing the flow of refrigerant around the evaporator. However, such systems normally include the attendant plumbing for affecting the by-pass.
The subject invention provides a compact by-pass arrangement that includes the valves and may be disposed next to or adjacent to the evaporator. The invention includes a valve body having a by-pass passage extending between the liquid and suction fluid lines, a by-pass valve at the intersection of the liquid fluid line and the by-pass passage. The by-pass valve has a normal operating position for directing fluid flow from the liquid fluid line to the evaporator and a by-pass position for directing fluid flow from the liquid fluid line to the by-pass passage. The valve also includes a by-pass check valve for allowing only one-way fluid flow through the by-pass passage when the by-pass valve is in the by-pass position.